Cook chicken. Heat a large pan over medium-high heat. Add 2 tablespoons of olive oil and then add chicken thighs one at a time. Let cook until skin is browned and they easily release from the pan (approximately 5-7 minutes). Flip and continue to cook until chicken is cooked through, approximately 5-7 minutes per side.
Cook aromatics. Add the remaining 2 tablespoons of olive oil to the pan along with the diced onions. Cook until onions are translucent. Approximately 3-4 minutes. Then add garlic and continue to cook for 1-2 minutes.
Cook pasta. Add the chicken broth, orzo, and about ½ teaspoon of salt. Use a wooden or silicone spoon to scrpe up any browned bits from the bottom of the pan.
Aparagus. Add the asparagus and bring to a boil, cover pan, and reduce heat to a simmer. Cook for approximately 8 – 10 minutes or until orzo is al dente and most of the liquid is absorbed.
Add lemon juice. Squeeze one lemon over the orzo, stir, and then add the chicken thighs back to the pan. Sprinkle with remaining parmesan cheese and serve.